Closures are typically used for facilitating the containment of, and permitting access to, a product stored in a container. There are a variety of types of conventional closures for containers. One type of prior art closure includes a body or base for being attached to the top of a container. The base defines an opening to the container interior. The closure further includes a lid which is hingedly mounted on the base and which can be lifted up to expose the closure base opening.
The inventor of the present invention has discovered that some closures molded from thermoplastic material have higher cost designs because of the greater amount of plastic material required. Also, some closures require a greater number of, or more complex, latching features for securely latching the lid closed on the closure base.
A typical conventional closure base and lid are adapted to “latch together” when the lid is in the closed position on the closure base. One typical type of such a latching system includes a laterally outwardly extending latch bead on a portion of the closure base and a laterally inwardly extending latch bead on a portion of the closure lid so that when the lid is in the closed position on top of, and at least partly overlapping a portion of the closure base, the lid latch bead lies below the closure base latch bead to create an interference resistance to opening the lid.
Typically, the closed lid must be initially subjected to an upwardly directed force applied by the user so as to effect sufficient temporary, elastic distortion or deformation of the closure lid and/or closure base in the region of the lid latch bead and closure base latch bead to permit the lid latch bead to be forced upwardly past, and become free of, the closure base latch bead. Thereafter, only a much reduced lift force is needed to continue moving the lid further upwardly to a fully opened (or at least sufficiently opened) position.
A manufacturer of a product may sell the product in a package consisting of a container in which the product is stored and on which the closure is installed. The inventor of the present invention has noticed that with some container/closure packages, the packages may be subjected to unintended, inadvertent, accidental impacts from, or engagements with, external structures or adjacent packages, and such impacts or engagements can overcome the latching resistance and dislodge the fully closed lid.
The inventor of the present invention has noticed that such lid-opening or lid-loosening impacts or engagements can occur during handling or shipping of the package by the manufacture of the product (especially when many identical packages are loaded together in a shipping carton or other transport device and subjected to shaking, bouncing, etc., during transportation). The inadvertent impacts caused during shipping may cause one or more package lids to become opened, or partially opened, or loose.
Some container/closure packages may be stored in an “inverted” orientation by the user. In such an inverted orientation, the container is supported by the closure which is at the bottom. During initial placement of the package in the inverted orientation, as well as during subsequent storage in the inverted orientation, the closure may be subjected to forces that could lead to an unintentional opening of the lid, or to loosening of the lid.
Another problem can occur when a user opens a closure lid and subsequently dispenses, or otherwise removes, some of the product from the container. Small quantities of the product may flow onto, drop onto, or otherwise contact a surface of the closure base. Over time, this can remain as an undesirable accumulation. The user may have difficulty in readily removing such accumulation from portions of the closure base.
The inventor of the present invention has discovered how to provide an improved closure which can accommodate designs that minimize, if not eliminate, one or more of the above-discussed problems. Further, such an improved closure can be designed to accommodate efficient, high-quality, high-speed, large volume manufacturing techniques with a reduced product reject rate to produce products having consistent operating characteristics unit-to-unit with high reliability.